1. Field of the Invention
This invention relates to an apparatus and method for mounting a device to a pipe.
2. Description of Related Art
Batch or continuous manufacturing and production processes in the chemical, food and other manufacturing industries employing a system of pipes for the conveyance of fluid materials often require mounting a variety of different devices, such as injectors and sensors, to the pipes of the system. Injectors are usually provided to introduce reagents, while sensors may measure such conditions as temperature, flow rate, or concentration of a reagent or product.
Exhaust purification systems for an internal combustion engines frequently contain injectors for the addition of reagents used in the exhaust purification process and sensors for measuring the concentration of various exhaust components. These systems frequently requires the installation or replacement of new injectors and sensors for optimizing the efficiency of the systems. For original equipment manufacturers, the installation of new injectors or sensors is usually performed at the engine manufacturing site, where the assembly and installation of equipment is not dictated by manufacturing method restrictions or by space or equipment constraints. However, for aftermarket modifications of internal combustion engine-powered systems (e.g., trucks, buses, cranes, welders), the installation of new injectors or sensors onto existing equipment or the replacement of already-installed injectors or sensors must often be performed at remote repair or retrofit facilities.
The current practice for the installation of injectors and sensors to metallic pipes is to drill a hole in the pipe, weld a fitting onto the pipe, and finally attach the injector or sensor to the fitting. For fixed engine exhaust systems, welding a fitting onto the exhaust pipe is particularly difficult because it may not be feasible to bring welding equipment to the site of the fixed engine. For vehicle-mounted exhaust systems, many repair facilities do not have access to welding equipment.
In addition, the welding of a fitting onto a pipe of an existing system may not be feasible because of difficulty of access to the pipe for lack of space. Frequently in vehicle exhaust systems there is only about 2–5 cm clearance between the exhaust pipe(s) and other parts of the vehicle or other equipment mounted to the vehicle. Also, welding a fitting onto the exhaust system of a vehicle may damage the engine or vehicle electronics, for example, by charge transfer processes.
Most exhaust systems for internal combustion engines include catalytic converters that are used in conjunction with various gas or fuel injectors and sensors for optimizing the operational efficiency of the catalytic converters. Frequently, lean oxides of nitrogen (NOx) catalysts, selective catalyst reduction (SCR) systems, and particulate filter systems employed for retrofit applications require the installation of an additional reagent injector and sensor. Injectors and sensors that are already installed in automobiles have special mounting structures that are attached or pre-formed into the exhaust pipe during manufacture. However, such manufacturing and mounting procedures are not usable for small-scale aftermarket retrofits.
Various apparatus for mounting injectors or sensors onto an exhaust system are known in the art.
U.S. Pat. No. 3,444,740 discloses an apparatus for measuring temperature where a wrap-around clamp secures a temperature measurement device in intimate contact with a pipe.
U.S. Pat. No. 4,364,226 discloses a device for inserting a sensor into an exhaust conduit of an internal combustion engine where the support of the sensor is formed by the sealing element of the assembly gaskets of the exhaust conduit.
U.S. Pat. No. 4,655,035 discloses an auxiliary air injector assembly for an exhaust pipe, with an injector fitting that is held in place in a hole in the pipe by the end of an air flow tube that is clamped against it by a saddle clamp extending around the pipe.
U.S. Pat. No. 4,746,223 discloses a meter for integrating the operating time of a steam trap, where a clamp is used to hold an electrolytic cell acting as a temperature sensor in close proximity to a pipe.
U.S. Pat. Nos. 5,522,218 and 5,605,042 disclose a combustion exhaust purification systems which includes injectors for injecting a NOx reducing fluid into an exhaust; however, no details of the installation of the injectors are described.
U.S. Pat. No. 6,050,088 discloses a mixture delivery device for introducing a reducing agent into an exhaust system containing an annular spray body inside the exhaust system. The patent illustrates this delivery device as being welded into an exhaust system.
U.S. Pat. No. 6,279,603 discloses an injector for a reducing reagent to improve the operation of a reducing catalytic converter, where the injector is mounted (e.g. by screw threading) to a sleeve welded to the exhaust pipe.
These and other documents cited in this application are incorporated into this application by reference.